Serum and serotonin induce retraction of calf aortic smooth muscle (CASM) cells in vitro: inhibition by ketanserin, a 5-HT2 receptor antagonist.
Calf aortic smooth muscle (CASM) cells cultured in vitro at high cell density (4 x 10(4) cells/cm2) on bacteriological petri dishes in the presence of serum pile up in clusters and create open spaces in the monolayer. This phenomenon is clearly visible 6 days after plating and is markedly enhanced by the addition of fetal calf serum. Serotonin is essential for the serum-induced retraction since (1) dialyzed serum has no effect, (2) of all the vasoactive agents we tested, only serotonin induced a similar degree of retraction, and (3) the serum-induced retraction was completely blocked by preincubating the cells with serotonin 5-HT2 receptor blockers such as ketanserin and ritanserin but not by preincubation with adrenergic-alpha 1 blockers or histamine antagonists. Serotonin caused CASM cell retraction in a dose-dependent way, with a maximum effect at 10(-6) M. The serotonin-induced retraction was reversible in time and was effectively blocked by ketanserin (IC50 = 1.2 x 10(-9) M). It is therefore concluded that serotonin induces retraction of CASM cells, mediated by the serotonin 5-HT2 receptor.
De Wever
B
B
Department of Cellular Biology and Pathology, Life Sciences, Janssen Research Foundation, Beerse, Belgium.
Rooman
R P
RP
De Brabander
M
M
D000818:Animals; D002417:Cattle; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D007650:Ketanserin / Q000494:pharmacology; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000187:drug effects / Q000648:ultrastructure; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology; D012701:Serotonin / Q000494:pharmacology*; D012702:Serotonin Antagonists; D012710:Serum Albumin, Bovine / Q000494:pharmacology*
D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D012710:Serum Albumin, Bovine; D012701:Serotonin; D007650:Ketanserin